“They called my management company and wanted to talk to me about doing a record. They sent me Undertow and I thought it was great but it was nothing like what I had been doing. I thought they had me confused with somebody else.

"A week later they called back and said they knew who I was and they wanted to fly me over. They didn’t want to have the people from the LA metal scene work on their record, they wanted it to be different.

"It turned out that their listening over the previous year was records I had done. I’d done a record with King Crimson; I did a project with David Sylvian and Robert Fripp that was a favourite of Adam [Jones, guitar]; then Maynard [Keenan, vocals] was keen on a lot of the world music I’d done at Real World. They’re so confident in their musical ability that they knew it wasn’t going to be bad, it was going to be different to what everyone else was doing and they were excited to try that.

"It was a great collaborative process, their style of music and my approach. On paper it probably didn’t look very good to the A&R people. But it came out as something unique.

"They’re incredible musicians - extraordinarily meticulous, great work ethics. They want it to be absolutely right but keeping the feel. They get to work every day ready to go. Not hung over, they’re ready to play, they’re on their marks and they work so hard writing the stuff that they don’t want to present it in a substandard way.

“Adam doesn’t get credited nearly as much as he should. What he does is unlike what any other guitar player I know does. His parts depend upon his tone. His pick striking - it's not shredding, the tone he gets and how he bends, where he hits the string and with what velocity, he works very hard on all of these elements on every part. It’s painstaking but the results are amazing.“